Sewing machine needle-actuating mechanism



A. 9. DE VOE 2,161,142

SEWING MACHINE NEEDLE ACTUATING MECHANISM 5 Sheets-Sheet 1 June 6, 1939 .v

Filed March 18 1938 Jlbet Jzpezbe 3 Sheets-Sheet 2 June 6, 1939. A. H DE voE SEWING MACHINE NEEDLEACTUATING MECHANISM Filed March 18, 193s June 6, 1939. A. H. DE VOE- 2,161,142

snwme MACHINE NEEDLE-ACTUATINGMECHANISM Fild March 18, 1938 3 Sheets-Sheet s Qqzzsew 911% do;

sewing machine frame.

Patented Jung 6, 1939,

UNI ED- TATES PATENT OFFICE SEWING. momma NEEDLE-ACTUATING- MECHANISM 9 Claims. (01. 112-221) This invention relates to sewing machines and has for an object to provide mechanism for actuating a reciprocatory eye-pointed sewing machine needle at higher operative speeds than have heretofore been successfullyattained.

The conventional needle-bar; such as heretofore used to carry the needle, has been eliminated and, in its stead, a needle is used having an integral shank which is slidably journaled in a guide-block detachably mounted on the sewing machine frame. The needle-shank is connected by a special working joint at its upper end to the lower end of a thin'plate-like pitman guided between spaced frame guide-blocks and carrying a crank-pin at its upper end which enters a hole in a cylindrical head on the rotary needle-baractuating shaft of the machine.

As the crank-pin substantially fills the hole in the cylindrical shaft-head, there is no unbalance caused by the use of the present crank and 1 no special crank-balancing means are required. The thin plate-like pitman is comparatively light in weight and, being held against sidewise buckv ling, forms a. light and strong linke connection between the crank and needle; the entire 'mecha nism, because of the lightness of the reciprocatory and oscillatory parts, is responsive to speeds of '8000 to 9000 R. P. M., of the top shaft without setting up serious or objectionable vibrations in the The invention will, be better understood by reference to the following detailed description of. one specific embodiment thereof. k

' In the accompanying drawings ,Fig. 1 is a front side elevation" of a sewing machine embodying the invention. Fig. 2 is a front erid ,elevation of the machine. Fig. 3 is a section on the line 3-3, FigT2. "Fig. 4 is a vertical section through the lower end of the needle and its guide. Fig. 5 is a disassembled perspective view of the needle and link and their guiding devices shown in Fig. 3. Fig. 6 is a perspective view of theinnenface of the upper end of the link shown in Fig. 5, and Fig. 7 is a sectional view of the special working 5 joint between the needle and its actuating link.

" The sewing machine in which the present improvement is embodied has a frame including ,the bed i and standard 2 of the gooseneck 3 terminating in the head 4.

Journaled in the gooseneck 3 is the top shaft 5 carrying the pulley 6 which is driven by the pulley 1 on the main shaft 8 to which it is connected by the conventional clip-belt 9.

The top-shaft 5 has a cylindrical head l0 hav- 55 ing a crank bearing aperture H for the crankattained in the present machine, is of great imits tapered lower end pin l2 normal to the thickened upper end l3 of the plate-like link H to which it is rigidly fixed.

The plate-like link I4 is formed at its thickened lower end with a lateral guide-pin I5 which is guidedto move in a right line by-the vertical guide-slot IS in the guide-block I! held in the frame-head 4 by screws l8, l8. The link I4 is also, formed at its lower end with one or more circular ribs 89 concentric with the axis of e pin I5. I 10 The frame head 4 has secured therein by screws 20, a second guide block 2! to which is detachably secured by screws 22 a section 23 formed with a guide hole 24 for the cylindrical shank 25 of the eye-pointed needle 26 for, which the block. 23 constitutes a sheath. The shank 25,:of the present needle isv of the same thickness as the con-- ventional sewing machine needle, to wit: .080 inch, and is about 1%, inches long; the conventional needle-shank length being about inch. .The weight of the present needle is about l gra m whereas the weight of a conventional round shank sewing machine needle is about .4 gram.

The present link it, exclusive of the crank-pin 1 2, weighs approximately. 10.2 gr ms whereas the conventional sewing machine needle-bar-actuatihg link weighs 21.4 grams. .Aconventiona'l hol- ,110W needle-bar weighs 26.5 grams. Hence, in the present machine, the total weight of the reciprocatory and oscillatory parts of the needlemechanismis 11.2 grams as compared to 48.3

I grams for the like parts of the conventional machine. 'The marked reduction of over 75% in the weight of the reciprocatory and oscillatory parts,

portance where ultra high-speed operation is contemplated.

The block 23 is so arranged that the axis of the hole 24, produced, intersects the axis of the pin 85. The needle-shank 25, Fig. 5, is formed in its side, near its upper end, with notches 21 to fit and receive the circular ribs IS on the link it. Thus, the circular ribs l9 transmit endwise reciprocatory motion to the needle 26, while permitting the link It to oscillate about the axis of the ribs E9. The guide-block 23 is formedabove the upper end of the hole 24 with a needle-shank guide-groove 28 of semi-circular cross-section to hold the needle-shank upon the circular ribs 19. The spaced opposed faces 2| of the block 2| and ll of the block I? guide and prevent buckling of the thin plate-like link !4. p

The sheath-like guide-block 23 is formed in @h a thread-guidingv groove 29, Fig, 4, which is in register with the needle-eye, circularly about the needle and serves to direct the end of sewing thread 30 into the eye 3! of the needle 26, when the latter is at its uppermost position. The groove 29 thus assists the operator in threading the needle.

The invention is not to be understood as limited to details of construction and relative arrangements of parts shown and described except as the prior art and the appended claims may require.

Having thus setforth the nature of the invention what I claim herein is:

1. Ina sewing machine, a bed and gooseneck, a rotary top shaft in said gooseneck, an eyepointed needle having an integral shank of conventional needle-shank diameter, a bearing in said gooseneck in which said'shank is endwise slidably fitted, a link connected at one end, to .said shaft, ,at the free end of said gooseneck,

" ,means independent of said needle-shank to guide the other end of saidelink to move in a right line, and means to transmit the right line movement of said other end of said link to said needleshank.

2. In a sewing machine, a frame comprising a bed and overhanging gooseneck, a rotary shaft in said'gooseneck, a crank driven by said. shaft, a thin plate-like link connected to be actuated by said crank, a reciprocatory needle connected to be actuated by said link, and stationary guides at opposite sides of said link to prevent buckling of the latter while under endwise compression forces. t

3. In a sewing machine, a'frame having a bearing, a needle having a shank slidably fitted in said bearing and formed in' one side with a notch, a link having at one end'a circular projection freely entering said notch, said frame having a guideway directly engaged by the end of said link having said projection to maintain said projection in said notch, a rotary shaft, and a crank driven by said shaft and connected to the other end of said link.

4. In asewing machine, a frame, a rotary shaft,

a crank driven thereby, athin plate-like link connected at one end to said crank and having at its other end a guide-pin and a circular rib coaxial with said guide-pin, means in said frame to guide said guide-pin, a needle having a shank formed with spaced notches embracing said circula-r rib, and a bearing in said. frame in which said needle-shank is slidably mounted.

5. In a sewing machine, a frame, a reciprocatory needle slidably journaled in said frame, a

rotary shaft journaled in said frame, a thin plate-like link connected at one end'to said needle, a crank connection between the other end of said link and said shaft, and spaced parallel guides on said frame between which said link operates, said guides servingto prevent buckling of said link under compressive forces.

6. In a sewing machine a frame, a rotary shaft journaled in said frame and having a cylindrical crank head, a crank-pin journaled in said crank-head with its axis parallel to and spaced from the axis of said shaft, a thin platelike link fixed at its upper end to said crankpin, means to guide the lower end of said link to move in a straight line, a reciprocatory needle actuated by said link, and guides on said frame to prevent sidewise buckling of said link.

' 7. In a sewing machine, a frame, an eyepointed needle having a shank of the conventional needle-shank diameter, a frame bearing block having a guideway in which said needleshank is slidably fitted, said needle-shank having a notch in one side, a crank-driven link having at one side a circular projection entering said notch and at the other side having a pin coaxialwith said projection, and means to guide said pin.

8. In a sewing machine, a frame, an eyepointed needle having a shank of the conventional needle-shank diameter, a frame bearing block having a guideway in which said needle-shank is slidably fitted, said needle-shank having a plurality of notches in one side, and a crank-driven link having at one side a plurality of concentric circular ribs entering the notches in said needleshank.

9. In a sewing machine, a reciprocatory eyepointed needle, a stationary sheath in which 

